CoJack is a new method to calculate and monitor pipe jacking online using non-linear constitutive equations to additionally take the load history of the pressure transfer rings and the resulting consequences of the load-distribution effects into account. Therefore, CoJack removes the risk factor of an overload of the pipes during the jacking and thus it decisively improves the safety and economic efficiency of jacking measures. It improves and provides for the supervision of jacking projects from the very first planning stage via the construction process to the final acceptance.